Conservation Science Blog

New research relevant to conservation in western North America

The Conservation Science Blog is intended to bring new and relevant research to the attention of conservation scientists, and facilitate discussion on how to apply this science to further conservation goals in western North America.

Posted on May 2, 2014 by Carlos Carroll

A new paper in the journal Science by Raquel Garcia and coauthors provides one of the first comprehensive reviews of how different aspects of climate change are projected to differentially affect the regions of the earth, and what those contrasts imply for biodiversity. Their findings suggest that while polar climates are projected to warm and shrink in area, the tropics will see the emergence of novel climatic conditions and undergo local changes in average climates beyond past variability. The review outlines a conceptual framework for classification of climate change metrics according to the types of threat and opportunity they are likely to impose on biodiversity, which can assist in planning to enhance climate resilience and adaptation potential.

Figure 3 from Garcia et al. 2014.

Posted on February 4, 2014 by Carlos Carroll

A great opportunity for someone with a background in conservation law and policy:

The Society for Conservation Biology (SCB) is a global community of conservation professionals with over 4,000 members (resource managers, educators, government and private conservation workers, informed members of the public, and students) dedicated to advancing the science and practice of conserving Earth’s biological diversity. More information about SCB can be found at: www.conbio.org.

SCB seeks a North American Policy Director (PD) to play two critical roles: (1) to advance the policy work of the North America Section in bringing conservation science to bear on the section’s priority policy initiatives, by means of outreach to agency and legislative staff, the scientific community, and the general public; and (2) to empower SCB’s members by providing them with the information and skills necessary to influence the policy process themselves.

The North American Policy Director is responsible for coordinating all of SCB’s policy activities in the U.S. and Canada, is expected to maintain an office in the Executive Office of SCB in Washington, D.C. This position requires experience in communications, building professional relationships with legislative and executive branches in Washington D.C., as well as administrative agencies working in conservation policy and management, and working with Canadian conservation scientists.

More information on the North America Section Policy Priorities can be found here.

Posted on December 16, 2013 by Carlos Carroll

A perceptive new paper by Dan Doak and colleagues in the journal TREE (link) critiques the “New Conservation Science” (NCS). NCS is a trend by some scientists and environmental NGOs to prioritize human-centered goals such as ecosystem services, and view as outdated efforts to protect biodiversity for its own sake. The authors conclude that the movement towards NCS is driven by values rather than science:

Despite claims that NCS approaches are supported
by biological and social science, NCS has limited
support from either. Rather, the shift in motivations and
goals associated with NCS appear to arise largely from a
belief system holding that the needs and wants of
humans should be prioritized over any intrinsic or inherent
rights and values of nature.

Posted on September 24, 2013 by Carlos Carroll

In a new study published in the journal Conservation Biology (link), researchers have found that long-term prospects for recovery of gray wolves in the western US may hinge on wolves being able to successfully disperse between widely-separated populations. While previous recovery efforts for wolves and other endangered species have acknowledged the importance of such connectivity, this study is perhaps the first times that detailed genetic and habitat data for any species have been used to project exactly how many dispersers are needed to sustain genetic health, and what areas offer the best prospects for dispersing wolves to move through. Although wolf recovery has achieved notable successes in areas such as Yellowstone National Park, the study’s findings suggest that long-term recovery may depend on overcoming barriers to dispersal in areas where wolf habitat is intermixed with ranchland and human settlements. “This study is the first time that scientists have taken a detailed look at what biology suggests is needed for long-term wolf recovery. Our findings imply that we can’t restore formerly widely-distributed species like the wolf to isolated populations in a few parks and expect them to remain genetically healthy”, said Dr. Carlos Carroll of the Klamath Center for Conservation Research.

The research group led by Dr. Carroll included two scientists from the Mexican Wolf Recovery Team. The Team was convened in 2010 to draft a recovery plan for the subspecies, which at only 75 individuals in the wild is among the most endangered mammals in North America. To support the Recovery Team effort, the scientists analyzed information on the pedigrees of wild and captive Mexican wolves, and forecast the potential future for Mexican wolves if their population remained isolated or was connected to other populations. They found that as isolated populations became increasingly inbred, the number of wolves in each litter declined, leading many populations to go extinct. Projections were made using a computer simulation model called Vortex developed by Dr. Robert Lacy of the Chicago Zoological Society (link). The researchers then used methods first developed to design electrical circuits (link) to map which areas of habitat held the best prospects for allowing dispersing wolves to survive and reach another population.

The study’s findings have implications for the current US Fish and Wildlife proposal to delist (remove federal protections for) wolves across the western US, outside of a single population of Mexican wolves in Arizona and New Mexico. Although the study is now completed, the Mexican Wolf Recovery Plan which spurred the research effort is on hold, after the last scheduled recovery team meeting in June 2012 was cancelled at short notice, a development that has been attributed to qualms about the political implications of the scientists’ findings (link).

Posted on August 16, 2013 by Carlos Carroll

On July 24, a symposium at the ICCB conference in Baltimore, Maryland brought together a multi-disciplinary group of biologists and policy experts from the US and Canada to address policy questions surrounding the definition of recovery, as well as the related issue of how planners can efficiently and transparently develop recovery criteria that guide recovery efforts.The US Endangered Species Act and Canada’s Species at Risk Act (SARA) are among the world’s most important biodiversity-related statutes. The Canadian federal government has suggested that SARA needs to be streamlined, in part by substituting ecosystem conservation for time-consuming recovery plans developed for individual species. In the US, recent reviews have proposed that, given the number of taxa which may require species-specific conservation measures in perpetuity, policymakers need to shift emphasis from long-term federal management of listed species to more rapid delisting that allows management by state and private entities. In contrast, others see such calls for more streamlined planning and management as undermining conservation of vulnerable taxa. In essence, this debate hinges on unresolved questions concerning how the public interprets the meaning of recovery and what cost it is willing to bear to achieve it. For some, recovery may imply self-sustaining populations that can play their historic role in ecosystems, whereas others see recovery of a small intensively-managed population as sufficient. The talks can be downloaded from the links given below.

Defining Recovery and Recovery Criteria for Endangered Species: Science and policy issues behind the current debate in the US and Canada

The Evolution Of US Policy On Endangered Species Recovery Since Passage Of The ESA. Dan Rohlf, Lewis and Clark University (slides)(audio)

Revisions of the US Endangered Species Recovery Planning Guidance. Debby Crouse, US Fish and Wildlife Service

A Risk-Based Approach To Recovery Planning Under SARA: A Case Study Of The Wide-Ranging And Elusive Woodland Caribou. Fiona Schmiegelow, University of Alberta (slides)(audio)

Posted on June 12, 2013 by Carlos Carroll

A lot of media attention continues to be focused on the question of whether and how wolves trigger trophic cascades in ecosystems, by suppression of herbivory by ungulates and consequent release of vegetation and species such as birds that are dependent on the vegetation for their habitat needs. Trophic cascades can be caused by numeric effects (declines in ungulate populations), behavioral effects (prey foraging differently and avoiding areas of high predation risk), or a combination of the two. Behavioral or non-consumptive effects can be linked to numeric effects when altered behavior leads to poorer nutrition and lower pregnancy rates.

This last effect has been proposed as a cause of elk declines in the Greater Yellowstone Ecosystem, but a new paper by Arthur Middleton and coauthors in Ecology Letters challenges that hypothesis, and finds that changes in elk behavior due to encounters with wolves have little effect on elk body fat or pregnancy rate, probably because elk encounter wolves infrequently (about every 9 days) in this area. This leaves open the possibility that wolves are contributing to elk population declines directly via predation. This last point has at times been missed by the media, resulting in headlines such as “wolves not to blame for elk decline”.

Another paper by the same research team found that a factor contributing to elk population declines in Yellowstone National Park was the decline in native cutthroat trout in Yellowstone Lake after nonnative lake trout were introduced. Because spawning cutthroat trout, but not lake trout, form an important food source for grizzly bears, the invasive speceis indirectly caused grizzly bears to shift their diet towards increased predation on elk calves, contributing to a decline in elk that had previously been attributed primarily to wolf predation (figure below).

While most research of wolf-induced trophic cascades has taken place in Yellowstone, two new papers test the trophic cascade hypothesis in the northcentral US and Poland. Both take a correlative approach that compares vegetation in areas with vs. without wolves. In Wisconsin, Ramana Callan and coauthors found that species richness of both forbs and shrubs was significantly higher in areas with high wolf use. This supports the hypothesis that wolves, by reducing the intensity of browsing by white-tailed deer, are reversing the biotic impoverishment of understory plant communities caused by decades of overabundant deer populations. Similar contrasts between areas of high and low wolf use were found by DPJ Kuijper and coauthors in Poland, where browsing intensity of tree saplings was lower inside wolf core areas. At a finer scale within wolf core areas, sites with more coarse-woody debris, which is an impediment to escape from wolf predation, had even lower browsing rates, supporting the conclusion that at least a portion of the effects on vegetation are behaviorally-mediated rather than solely due to lower numbers of ungulates.